Hayabusa’s bounty
Is this the most valuable five grams on the planet?
There’s nothing quite as pleasurable as exceeding expectations. Japanese scientists have peeked inside the sample capsule from Japan’s Hayabusa2 sample-return mission and found it to contain 5.4 grams of material from asteroid 162173 Ryugu.
“[That’s] far above the target of one-tenth of a gram,” said Hitoshi Kuninaka, vice-president of the Japan Aerospace Exploration Agency (JAXA) at a meeting of the international Committee on Space Research (COSPAR). The sample looks like coarse black sand, he added. “The largest grain is one centimetre.”
The material was collected in 2019 and arrived on Earth on 6 December 2020, when the spacecraft flew by and ejected its sample container to a landing site at Woomera, in South Australia. Japanese scientists retrieved it and whisked it back to Japan, where they first secured it from any risk of contamination from the Earth’s atmosphere, then set to work on opening it.
Detailed study, Kuninaka said, will begin in May or June, after the grains are catalogued and parcelled out to scientists not only in Japan, but Australia, Europe and America. Already, he says, the team has analysed gases emitted by the asteroid material (though the results have not yet been released).
Future Japanese samplereturn missions will continue to collaborate with Australia, with the next one scheduled for 2029.
That mission’s targets are the moons of Mars, where it hopes to collect a sample from the larger one, Phobos. Called MMX (Mars Moons exploration), the mission is scheduled for launch in 2024 and will reach Mars in 2025. It will then spend three years studying the moons before sending its sample back to Earth.
“We are thinking [of ] further sample-return missions in the future,” Kuninaka said. “Periodic sample return is our promise to the science community in the world.”
These missions are just part of an ambitious fleet of Japanese space missions, he said.
JAXA is collaborating with the European Space Agency on the Bepicolombo mission, currently en route to Mercury, where it hopes to learn how the planet’s magnetic field interacts with the nearby Sun’s harsh solar wind.
JAXA also has a spacecraft called Akatsuki, currently studying the upper atmospheric winds and meteorology of
Venus, and one in development called DESTINY+, which will use experimental propulsion technologies to fly by the asteroid 3200 Phaeton (believed to be the parent body for the Geminid meteor shower) in 2028.
Meanwhile Hayabusa2 is far from finished. As it flew by Earth to eject its precious cargo from Ryugu, it used Earth’s gravity to alter course toward another nearearth asteroid, the 710-metre (98943) 2001 CC21.
This time, however, it’s a oneway trip: a flyby that will occur in July 2026. Officially, it’s called an “extended mission”. Unofficially, it’s a twofer – an opportunity to draw more information from a spacecraft that has already exceeded expectations.